Fixing an USB charger

[tsimoes]

My first post here so thanks for this amazing site.

I decided to fix an damaged 4 port usb charger. It´s been sitting in my desk for quite some time so now is its time.

I opened and saw right away a puffed out component. Since I´m not an electronics professional, I first thought it was a capacitor.
But the image on the board tells something different. Like this:

The markings on the component are very hard to read but it shows something like: "227336"
Any ideas?

 

[danadak]

Can you [post a well focused pic of the board ?

Regards, Dana.

 

[tsimoes]

Of course. Sorry about that.
#1 - is the whole board
#2 - One part zoomed in
#3 - Another part zoomed in
#2 and #3 are complementary

 

[Martaine2005]

L3 is an inductor. You might get lucky by entering ‘inductor’ followed by the number on the component into your favourite search engine.

Edit: I’d be surprised if that component is faulty. Not impossible but unlikely.

Martin

 

[bertus]

Hello,

Is the fuse next to the yellow capacitor OK?
It is marked F1.

Bertus

 

[tsimoes]

Yeah, I thought I had correctly identified the problem, but I may be wrong.
I know how to identify a faulty capacitor and initially I thought it was a capacitor.
But I take new pictures...
#4 is the "faulty inductor"
#5 is a close up of the fuse. I don't think is broken. Maybe if I test the two points?

 

[bertus]

Hello,

A fuse should show a very low value at the resistance measurement of the meter.
Also the inductor should show a low value at the resistance measurement of the meter.

Bertus

 

[Martaine2005]

Yes, you’ll need to check continuity across the fuse. The inductor is not the cause here.
Also, a failed capacitor doesn’t always give a visual indication. Check the fuse first with your multimeter or continuity tester. If it’s blown, don’t replace it just yet. Someone on here will assist you with checking other components.

Martin

 

[tsimoes]

I did both tests.
The fuse seems to be working since I can read continuity on both ends.
The inductor is reading 0,05 when my voltmeter is set to 200 ohm. (see on the web that is a valid test...)

 

[H2814D]

I have repaired several USB Power Supplies of different types. One of the most common failures is that smaller 10uF/50Volt Capacitor on the board next to the transformer. If the Inductor has continuity, it is probably good. Replace that 10uF Cap and see what happens. Let us know please.

 

[tsimoes]

I´ll take a look at that and get back here. Just a curiosity, the temperature that is specified when you buy such pieces, is relevant? Because I can´t seen to find in the original piece...

 

[H2814D]

I´ll take a look at that and get back here. Just a curiosity, the temperature that is specified when you buy such pieces, is relevant? Because I can´t seen to find in the original piece...

There are two most common temperature ratings for these caps. 85C and 105C. Both of them are easily sourced. I always go with the higher temperature when replacing components, since the cost difference is usually minimal. For a USB Charger, however, I wouldn't think it would matter much. Try and find the 105C though. Good luck.